Explanation

A reflecting telescope uses two mirrors:

1. The primary mirror (which collects and focuses light).
2. The secondary mirror (which directs the focused light to the eyepiece), to form an image of distant objects.

Explanation

Undersea earthquakes displace a large volume of water, generating powerful sea waves.

This sudden movement creates a tsunami, which can travel across oceans at high speeds.

Explanation

The mesosphere is the coldest layer of the atmosphere, with temperatures dropping as low as -90°C.

It lies above the stratosphere and below the thermosphere.

Explanation

Magnetic lines of force always form closed loops from the north pole to the south pole outside the magnet and continue inside the magnet.

They never start or end abruptly like electric field lines.

Explanation

Kilowatt-hour (kWh) is a unit of electrical energy.

It represents the energy consumed when 1 kilowatt of power is used for 1 hour.

Explanation

Explanation

Displacement is a vector quantity because it has both magnitude and direction.

Distance, speed, and time are scalar quantities — they have only magnitude.

Explanation

Explanation

Longitudinal waves are also called: Compressional waves, Pressure waves, Compression waves.

A longitudinal wave is a wave in which the particles of the medium vibrate in the same direction as the wave propagates.

Explanation

Work, mass and distance are scalar quantities because they have magnitude but no direction, but they are not vector quantities.

Vector Quantities: Velocity, momentum, torque, acceleration, weight, displacement.

Scalar Quantities: Work, distance, speed, mass.